"Video still capture" involves a process of extracting a still image from an image set comprising a sequence of electronically-encoded image frames. A number of video capture products are on the market that allow a user to capture one or more still images from a conventional video source to an attached computer, such as a personal computer (PC). The video source can be a signal conforming to one of the well-known NTSC, PAL, or SECAM video standards, or a video camera, or sequential images from a digital camera, or recorded bvideo signals played on a video cassette recorder (VCR) or the like.
Many video sources, such as consumer-quality computer cameras and consumer VCRs, tend to have noise problems that degrade image quality. When capturing single video frames for display as still images, these problems are still visible. Some attempts have been made to reduce such noise. For example, the SNAPPY.TM. video snapshot product from Play, Inc. generates an unweighted average of multiple video fields without any motion compensation to output a single still image with somewhat reduced noise.
The inventor has determined that there is still a need for improved noise reduction in a video capture system. The present invention provides a method and system for achieving this end.